Two hundred white elderly Americans, living independently, will be compared with fifty (50) unable to live on their own. All will have yearly physical and laboratory examinations, computerized tomographic studies of the brain and the Older American Resources and Services (OARS) questionnaire, psychological tests, psychiatric interviews, laboratory examinations and physical examinations. During this year all two hundred of the subjects have been completed for their first examination. Eighty-four of the independently living elderly have been retested. An attempt is now being made to enroll the fifty subjects living in institutional settings. Preliminary data from the first year study of the 200 subjects indicate that only the psychological examinations and the laboratory examinations (SMA12) can differentiate between those who have atrophy from those who do not have atrophy. A comparison of the first year data with the second year data is now underway and it is assumed that this will reveal individual differences. Similarly collection and analysis of the institutionalized subjects' testing when compared to the independent subjects' tests will begin to reveal information concerning factors leading to independent living.